Cathode Ray Tube

1. The problem statement, all variables and given/known data
A positively charged particle of mass 7.2 * 10^-8kg is travelling east with speed of 85 m/s. The particle enters a 0.31 T uniform magnetic field, and 2.2 * 10^-3 secounds later leaves the field one-quarter south with speed of 85 m/s. What is the charge of the particle and magnetic force?